linq Standard Query Operators Sorting Operations

Example

A sorting operation orders the elements of a sequence based on one or more attributes.

OrderBy

Sorts values in ascending order.

Method Syntax

// OrderBy

var numbers = new int[] { 5, 4, 8, 2, 7, 1, 9, 3, 6 };

var ordered = numbers.OrderBy(n => n);

// ordered = { 1, 2, 3, 4, 5, 6, 7, 8, 9 }

Query Syntax

// orderby

var numbers = new int[] { 5, 4, 8, 2, 7, 1, 9, 3, 6 };

var ordered = from n in numbers
              orderby n
              select n;

// ordered = { 1, 2, 3, 4, 5, 6, 7, 8, 9 }

---

OrderByDescending

Sorts values in descending order.

Method Syntax

// OrderByDescending

var numbers = new int[] { 5, 4, 8, 2, 7, 1, 9, 3, 6 };

var ordered = numbers.OrderByDescending(n => n);

// ordered = { 9, 8, 7, 6, 5, 4, 3, 2, 1 }

Query Syntax

// orderby

var numbers = new int[] { 5, 4, 8, 2, 7, 1, 9, 3, 6 };

var ordered = from n in numbers
              orderby n descending
              select n;

// ordered = { 9, 8, 7, 6, 5, 4, 3, 2, 1 }

---

ThenBy

Performs a secondary sort in ascending order.

Method Syntax

// ThenBy

string[] words = { "the", "quick", "brown", "fox", "jumps" };

var ordered = words.OrderBy(w => w.Length).ThenBy(w => w[0]);

// ordered = { "fox", "the", "brown", "jumps", "quick" }

Query Syntax

// orderby …, …

string[] words = { "the", "quick", "brown", "fox", "jumps" };

var ordered = from w in words
              orderby w.Length, w[0]
              select w;

// ordered = { "fox", "the", "brown", "jumps", "quick" }

---

ThenByDescending

Performs a secondary sort in descending order.

Method Syntax

// ThenByDescending

string[] words = { "the", "quick", "brown", "fox", "jumps" };

var ordered = words.OrderBy(w => w[0]).ThenByDescending(w => w.Length);

// ordered = { "brown", "fox", "jumps", "quick", "the" }

Query Syntax

// orderby …, … descending

string[] words = { "the", "quick", "brown", "fox", "jumps" };

var ordered = from w in words
              orderby w.Length, w[0] descending
              select w;

// ordered = { "the", "fox", "quick", "jumps", "brown" }

---

Reverse

Reverses the order of the elements in a collection.

Method Syntax

// Reverse

var numbers = new int[] { 1, 2, 3, 4, 5 };

var reversed = numbers.Reverse();

// reversed = { 5, 4, 3, 2, 1 }

Query Syntax

// Not applicable.